CFD Simulation of Chemical Reactors: Development and Experimental Validation of Micromixing Models for Product Selectivity (TSE99-F)

Iowa State University, Ames IA

Investigators

Abstract

The reduction of pollution and toxic byproducts caused by poor product selectivity is a critical step towards the development of environmentally-friendly, sustainable chemical processes. Macroscopic models based on computational fluid dynamics (CFD) have potential for improving process design in the chemical process industry. However, the ultimate utility of using CFD for reducing pollution and toxic byproduct caused by poor product selectivity depends on the development and validation of micromixing models needed to describe the complex interactions between turbulent mixing and chemical reactions at the sub-grid scale. To date, no detailed experimental data for both the turbulent flow field and the concentration fields inside of a liquid-phase chemical reactor are available for model validation. In this research project, the PI's plan to address this significant shortcoming by obtaining such data for a well-defined reactor geometry (i.e., a channel-flow reactor) under carefully controlled operating conditions using particle-image velocimetry (PIV) and planar laser-induced fluorescence (PLIF). In addition, in order to extract flow statistics that cannot easily be measured with PIV/PLIF, direct numerical simulations (DNS) and large-eddy simulations (LES) will be performed for the same reactor geometry. These data will be employed to validate CFD models for turbulent transport and the chemical source term. If successful, the project will provide detailed data for CFD model validation of liquid-phase chemical reactors. The experimental facility will be designed and built in collaboration with researchers at The Dow Chemical Company. As part of the Vision 2020 initiative, Dow has identified CFD validation as an important long-term goal towards advanced chemical reactor design. One PI has collaborated with Dow since 1992 on CFD modeling of chemical reactors and this project directly addresses shortcomings of existing CFD models that were identified in earlier industrial collaborations. The project will thus have an impact on industrially relevant issues related to pollution prevention and avoidance at the source.